Since the inception of the tolling concept nearly 3,000 years ago in the Middle East, there has been a common source of frustration that has only been addressed in the last few decades.

Whether someone is driving a horse and buggy or a four-door sedan, the frustration of having to slow down and dig for payment before continuing on our journey has always been a tedious interruption to our travels.

With the welcome emergence of all-electronic tolling (AET), consumers are excited and relieved to be able to whiz along the road without interruption, except for the occasional “Are we there yet?” of course. AET is a true innovation in the toll world. While AET has brought many positives to tolling, it has also left us with another set of issues to resolve: interoperability.

Bridging the technology gap (again and again)

The emergence of AET has provided both consumers and toll operators with streamlined travel, operations and all-around cost savings. Many toll operators have already made the switch to AET, yet there are others still considering the changeover to this fairly new technology. Operators considering the switch to AET commonly wonder if technology is advancing so quickly that they will get the AET switch made only to have a newer, better option available shortly thereafter. Additionally, the vehicle-miles traveled (VMT) tax debate further complicates whether now is the right time to invest in AET technology.

These ever-changing technologies and policies highlight the need for both an open and modular system design as well as standard interfaces and protocols. By using an open design, operators are able to keep the system current by using subsystem replacements rather than having to replace the entire system when technology enhancements become available. Additionally, the flexibility of integrating emerging technologies in open-architecture systems provides lower maintenance costs.

Open to the future

Using a system that complies with open standards that are verified by certification organizations is essential for systems and data to be interoperable. Without open standards, data can realize only a fraction of its value. Building on open standards will allow authorities to take full advantage of lower costs and standardized testing as it helps data from different sources work together. It also ensures that users are never locked into their current data systems.

AET can be applied to several different tolling scenarios. In an AET scenario, there are no tollbooths, collectors or cash. Instead, cars pass through toll zones at highway speeds, while tolls are collected electronically by capturing data from a car’s toll tag or license plate. There is no need for cars to slow down, employ a person to handle cash or construct expensive facilities, equipment or safety precautions that are needed with manual toll roads. This approach provides significant operational cost savings.

In recent years there has been an increase in the construction of high-occupancy toll (HOT) lanes and managed lanes. HOT lanes are open to vehicles with more than one occupant, but single-occupant vehicles also can take advantage of the designated lanes by paying a toll. In the case of managed lanes, the toll operator guarantees trip times or a minimum speed from one destination to another by managing the amount of traffic and monitoring the speed in those designated lanes. By using real-time traffic-monitoring technology and integrating data from other lanes and toll roads, operators can determine congestion levels in near real-time and accordingly adjust the tolls to ensure guaranteed speed and trip times.

Whether used in a HOT lane or a managed lane, the concept of AET is the same: It provides a complete management platform and real-time diagnostics for tolling networks. This information is critical to charging consumers correctly and is especially critical to interoperability transactions. As toll-collection systems serve as revenue-collection systems, it is important for the data to be up-to-date for accurate transaction processing and auditing.

As with financial point-of-sale systems, the information can be acquired by various types of hardware, however the exchange of the transactional information has a common and standard interface. The toll industry, in some cases, is developing standards and protocols for this type of transactional-information exchange. There are others that believe having standards for the hardware is the answer to interoperability, and thus, the debate begins.

Match making

One of the key features of an AET system is the software that can identify and match vehicles to accounts in order to collect fares. This is often easier said than done, as optical-character-recognition (OCR) software must be able to take into account other distinguishing characteristics besides a license plate, which may be dirty or hard to capture because of personalization or varying designs and graphics. By using other distinguishing marks on the vehicle, such as logos, stickers and lights, OCR software can better determine the identity of the vehicle’s registered owner.

If an automatic match is not generated from the car tag or license-plate recognition, the OCR then compares the vehicle descriptors to entries in a database. If there is a high level of confidence in the identification of the vehicle, a bill is mailed to the registered owner. This process of “match making” increases the integrity of a transaction and is critically important for charging as well as for interoperability.

The process of identifying a car and mailing a bill to the owner may not always be worth the value of an inexpensive toll. In these cases, the managing authority should rely on highly flexible and configurable AET software that can adjust to these particular needs and business rules.

Electing electronics

The Central Texas Regional Mobility Authority (CTRMA) is an independent government agency created to develop and improve transportation projects in Texas. When the CTRMA was created, there were approximately three other toll agencies with operating toll roads. Traditionally, the region’s toll roads had operated with the typical barrier and cash systems. To improve efficiencies and traffic congestion, CTRMA worked with Schneider Electric on the design, development and installation of a manual-collection system, electronic-toll collection and open-road-tolling system on toll road 183A.

But as the area’s population and traffic continued to increase over the next several years, and as other toll agencies were authorized and developed projects, CTRMA searched for new ways to efficiently manage and collect tolls from the nearly 100,000 vehicles per day that traveled on toll road 183A. CTRMA made the bold move to remove all cash lanes along the road and implement an all-electronic system to reduce congestion and save money. The project used a combination of electronic-toll collection, open-road-tolling/free-flow zones and video tolling. It was one of the first AET-collection systems in the U.S.

CTRMA is in close proximity to the Texas Department of Transportation (TxDOT) system and not too far from Dallas and Houston, so interoperability was a leading factor in the development of the business rules and protocols that make up the agency’s toll-collection system. The question of interoperability has been an issue beginning with cities, regions and states and is now on an even broader, national level.

Implementation lessons

CTRMA required the tolling system to read two differing but compatible tag types: battery tags deployed in Houston and sticker tags from the Austin and Dallas areas. Each tag operates at different power levels and distinct read ranges, which can result in many tag-assignment errors. Accuracy from the system was critical to reduce missed tag assignments, wrong tag assignments and other errors that create a larger demand for review in the operator’s office.

To overcome errors, a specialized algorithm was used to refine the accuracy of tag assignments by reporting the relative speed of the tag. The algorithm was implemented by placing the tag in a specific location, a move that allows the system to determine when the tag passes under the antenna with a very high level of precision. This provides CTRMA with an extremely accurate tag assignment. The data collection also has solved the issues of reader tuning for different tag types and virtually eliminated tag read assignment inaccuracies.

In the case of CTRMA, the decision to go all-electronic was easily justifiable. Between the reductions of the cost to collect cash transactions combined with relatively little system software changes, switching to AET greatly improved operations.

The results

CTRMA is now able to accurately monitor toll-system operations and maintenance management to ensure reliability and accuracy of the entire toll system.

Tolling is a key funding tool for state transportation projects, and profitability of toll roads has increased thanks to the enormous costs that have been avoided with the AET system: CTRMA estimates that $1 million to $2 million has been saved solely from converting to AET on the 183A project.

These savings have been used to extend 183A 16 miles and add AET to a second road, 290 East. In fact, not only have the increased savings been used for additional infrastructure projects, but also for improving the community. CTRMA has expanded its HERO program, which provides free roadside assistance and aid to stranded motorists in order to help minimize traffic congestion and improve road safety. Thanks to these proven AET results, CTRMA has declared that every future toll road will be all-electronic.

As mentioned above, one of the biggest challenges with any AET implementation is the accuracy of vehicle identification. In the case of CTRMA, vehicle identification accuracy has achieved 99.97% among the 6.9 million transactions each year.

The road ahead

The biggest challenges over the next several years will be the continued improvement and refining of tolling solutions that are flexible enough to handle varying operational rules, as well as the ability to efficiently and accurately identify vehicle ownership and equitably collect fares. One of the most significant improvements in this area will depend on the toll industry’s ability to agree on and develop common platforms and requirements for exchanging transactional information while keeping charging mechanisms convenient for users.

The fact that tax revenues are not sufficient to pay for the maintenance of existing infrastructure—not to mention covering new infrastructure costs—will continue to spur user-based charging schemes. The popularity of AET will not go away anytime soon. There is an enormous opportunity to create an interoperable network that allows toll operators the assurance and integrity of existing financial networks, while operating independently and customized for customers they serve.